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Mi H, MacLaren RE, Cehajic-Kapetanovic J. Robotising vitreoretinal surgeries. Eye (Lond) 2024:10.1038/s41433-024-03149-3. [PMID: 38965320 DOI: 10.1038/s41433-024-03149-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 03/04/2024] [Accepted: 05/17/2024] [Indexed: 07/06/2024] Open
Abstract
The use of robotic surgery in ophthalmology has been shown to offer many potential advantages to current surgical techniques. Vitreoretinal surgery requires complex manoeuvres and high precision, and this is an area that exceeds manual human dexterity in certain surgical situations. With the advent of advanced therapeutics such as subretinal gene therapy, precise delivery and minimising trauma is imperative to optimize outcomes. There are multiple robotic systems in place for ophthalmology in pre-clinical and clinical use, and the Preceyes Robotic Surgical System (Preceyes BV) has also gained the CE mark and is commercially available for use. Recent in-vivo and in-human surgeries have been performed successfully with robotics systems. This includes membrane peeling, subretinal injections of therapeutics, and retinal vein cannulation. There is huge potential to integrate robotic surgery into mainstream clinical practice. In this review, we summarize the existing systems, and clinical implementation so far, and highlight the future clinical applications for robotic surgery in vitreo-retina.
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Affiliation(s)
- Helen Mi
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Robert E MacLaren
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Jasmina Cehajic-Kapetanovic
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
- NIHR Oxford Biomedical Research Centre, Oxford, UK.
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2
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Waldock WJ, Taylor LJ, Sperring S, Staurenghi F, Martinez-Fernandez de la Camara C, Whitfield J, Clouston P, Yusuf IH, MacLaren RE. A hypomorphic variant of choroideremia is associated with a novel intronic mutation that leads to exon skipping. Ophthalmic Genet 2024; 45:210-217. [PMID: 38273808 DOI: 10.1080/13816810.2023.2270554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/09/2023] [Indexed: 01/27/2024]
Abstract
INTRODUCTION Molecular confirmation of pathogenic sequence variants in the CHM gene is required prior to enrolment in retinal gene therapy clinical trials for choroideremia. Individuals with mild choroideremia have been reported. The molecular basis of genotype-phenotype associations is of clinical relevance since it may impact on selection for retinal gene therapy. METHODS AND MATERIALS Genetic testing and RNA analysis were undertaken in a patient with mild choroideremia to confirm the pathogenicity of a novel intronic variant in CHM and to explore the mechanism underlying the mild clinical phenotype. RESULTS A 42-year-old male presented with visual field loss. Fundoscopy and autofluorescence imaging demonstrated mild choroideremia for his age. Genetic analysis revealed a variant at a splice acceptor site in the CHM gene (c.1350-3C > G). RNA analysis demonstrated two out-of-frame transcripts, suggesting pathogenicity, without any detectable wildtype transcripts. One of the two out-of-frame transcripts is present in very low levels in healthy controls. DISCUSSION Mild choroideremia may result from +3 or -3 splice site variants in CHM. It is presumed that the resulting mRNA transcripts may be partly functional, thereby preventing the development of the null phenotype. Choroideremia patients with such variants may present challenges for gene therapy since there may be residual transcript activity which could result in long-lasting visual function which is atypical for this disease.
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Affiliation(s)
| | - Laura J Taylor
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Sian Sperring
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Federica Staurenghi
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Cristina Martinez-Fernandez de la Camara
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | | | - Penny Clouston
- Oxford Regional Genetics Laboratories, Churchill Hospital, Oxford, UK
| | - Imran H Yusuf
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Robert E MacLaren
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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Ruggeri F, Ciancimino C, Guillot A, Fumi D, Tizio FD, Fragiotta S, Abdolrahimzadeh S. Posterior Polar Annular Choroidal Dystrophy: Genetic Insights and Differential Diagnosis in Inherited Retinal Diseases. Curr Issues Mol Biol 2024; 46:1383-1397. [PMID: 38392207 PMCID: PMC10887594 DOI: 10.3390/cimb46020089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 01/28/2024] [Accepted: 02/02/2024] [Indexed: 02/24/2024] Open
Abstract
Posterior polar annular choroidal dystrophy (PPACD) is a rare ocular disorder and presents as symmetric degeneration of the retinal pigment epithelium (RPE) and the underlying choriocapillaris, encircling the retinal vascular arcades and optic disc. This condition distinctively preserves the foveal region, optic disc, and the outermost regions of the retina. Despite its distinct clinical presentation, due to the infrequency of its occurrence and the limited number of reported cases, the pathophysiology, and the genetic foundations of PPACD are still largely uncharted. This review aims to bridge this knowledge gap by investigating potential genetic contributors to PPACD, assessing current findings, and identifying genes that warrant further study. Emphasis is also placed on the crucial role of multimodal imaging in diagnosing PPACD, highlighting its importance in understanding disease pathophysiology. By analyzing existing case reports and drawing comparisons with similar retinal disorders, this paper endeavors to delineate the possible genetic correlations in PPACD, providing a foundation for future genetic research and the development of targeted diagnostic strategies.
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Affiliation(s)
- Francesco Ruggeri
- Ophthalmology Unit, Neurosciences, Mental Health, and Sense Organs (NESMOS) Department, Faculty of Medicine and Psychology, University of Rome Sapienza, 00185 Roma, Italy
| | - Chiara Ciancimino
- Ophthalmology Unit, Neurosciences, Mental Health, and Sense Organs (NESMOS) Department, Faculty of Medicine and Psychology, University of Rome Sapienza, 00185 Roma, Italy
| | - Antonio Guillot
- Ophthalmology Unit, Neurosciences, Mental Health, and Sense Organs (NESMOS) Department, Faculty of Medicine and Psychology, University of Rome Sapienza, 00185 Roma, Italy
| | - Daniele Fumi
- Ophthalmology Unit, Neurosciences, Mental Health, and Sense Organs (NESMOS) Department, Faculty of Medicine and Psychology, University of Rome Sapienza, 00185 Roma, Italy
| | - Federico Di Tizio
- St. Andrea Hospital, Via di Grottarossa 1035/1039, 00189 Rome, Italy
| | - Serena Fragiotta
- UOC Ophthalmology, Department of Surgical Areas, S.M. Goretti Hospital, 04100 Latina, Italy
| | - Solmaz Abdolrahimzadeh
- Ophthalmology Unit, Neurosciences, Mental Health, and Sense Organs (NESMOS) Department, Faculty of Medicine and Psychology, University of Rome Sapienza, 00185 Roma, Italy
- St. Andrea Hospital, Via di Grottarossa 1035/1039, 00189 Rome, Italy
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4
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Han RC, Taylor LJ, Martinez-Fernandez de la Camara C, Henderson RH, Thompson DA, Cehajic-Kapetanovic J, MacLaren RE. Is RPGR-related retinal dystrophy associated with systemic disease? A case series. Ophthalmic Genet 2023; 44:577-584. [PMID: 36602268 DOI: 10.1080/13816810.2022.2163405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/30/2022] [Accepted: 12/23/2022] [Indexed: 01/06/2023]
Abstract
BACKGROUND Ciliopathies responsible for retinitis pigmentosa can also cause systemic manifestations. RPGR is a ciliary gene and pathogenic variants in RPGR cause a retinal ciliopathy, the commonest cause of X-linked recessive retinitis pigmentosa. The RPGR protein interacts with numerous other ciliary proteins present in the transition zone of both motile and sensory cilia, and may play an important role in regulating ciliary protein transport. There has been a growing, putative association of RPGR variants with systemic ciliopathies: mainly sino-respiratory infections and primary ciliary dyskinesia. MATERIALS AND METHODS Retrospective case series of patients with RPGR-RP presenting to Oxford Eye Hospital with systemic disease. RESULTS We report three children with RPGR-related rod-cone dystrophy, all of whom have mutations in the N-terminus of RPGR. Two cases co-presented with confirmed diagnoses of primary ciliary dyskinesia and one case with multiple sino-respiratory symptoms strongly suggestive of primary ciliary dyskinesia. These and all previously reported RPGR co-pathologies relate to ciliopathies and have no other systemic associations. CONCLUSIONS The link between RPGR variants and a systemic ciliopathy remains plausible, but currently unproven.
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Affiliation(s)
- Ruofan Connie Han
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Laura J Taylor
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | | | - Robert H Henderson
- Department of Ophthalmology, Great Ormond Street Children's Hospital, London, UK
| | - Dorothy A Thompson
- Department of Ophthalmology, Great Ormond Street Children's Hospital, London, UK
- Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children, London, UK
| | - Jasmina Cehajic-Kapetanovic
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Robert E MacLaren
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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Gocuk SA, Jolly JK, Edwards TL, Ayton LN. Female carriers of X-linked inherited retinal diseases - Genetics, diagnosis, and potential therapies. Prog Retin Eye Res 2023; 96:101190. [PMID: 37406879 DOI: 10.1016/j.preteyeres.2023.101190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 07/07/2023]
Abstract
Inherited retinal diseases (IRDs) are a group of heterogeneous conditions that cause progressive vision loss, typically due to monogenic mutations. Female carriers of X-linked IRDs have a single copy of the disease-causing gene, and therefore, may exhibit variable clinical signs that vary from near normal retina to severe disease and vision loss. The relationships between individual genetic mutations and disease severity in X-linked carriers requires further study. This review summarises the current literature surrounding the spectrum of disease seen in female carriers of choroideremia and X-linked retinitis pigmentosa. Various classification systems are contrasted to accurately grade retinal disease. Furthermore, genetic mechanisms at the early embryonic stage are explored to potentially explain the variability of disease seen in female carriers. Future research in this area will provide insight into the association between genotype and retinal phenotypes of female carriers, which will guide in the management of these patients. This review acknowledges the importance of identifying which patients may be at high risk of developing severe symptoms, and therefore should be considered for emerging treatments, such as retinal gene therapy.
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Affiliation(s)
- Sena A Gocuk
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Victoria, Australia; Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia
| | - Jasleen K Jolly
- Vision and Eye Research Institute, Anglia Ruskin University, Cambridge, UK
| | - Thomas L Edwards
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia
| | - Lauren N Ayton
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Victoria, Australia; Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia.
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6
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Yusuf IH, MacLaren RE. Choroideremia: Toward Regulatory Approval of Retinal Gene Therapy. Cold Spring Harb Perspect Med 2023; 13:a041279. [PMID: 37277205 PMCID: PMC10691480 DOI: 10.1101/cshperspect.a041279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Choroideremia is an X-linked inherited retinal degeneration characterized by primary centripetal degeneration of the retinal pigment epithelium (RPE), with secondary degeneration of the choroid and retina. Affected individuals experience reduced night vision in early adulthood with blindness in late middle age. The underlying CHM gene encodes REP1, a protein involved in the prenylation of Rab GTPases essential for intracellular vesicle trafficking. Adeno-associated viral gene therapy has demonstrated some benefit in clinical trials for choroideremia. However, challenges remain in gaining regulatory approval. Choroideremia is slowly progressive, which presents difficulties in demonstrating benefit over short pivotal clinical trials that usually run for 1-2 years. Improvements in visual acuity are particularly challenging due to the initial negative effects of surgical detachment of the fovea. Despite these challenges, great progress toward a treatment has been made since choroideremia was first described in 1872.
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Affiliation(s)
- Imran H Yusuf
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, United Kingdom
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, United Kingdom
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7
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Chern KJ, Nettesheim ER, Reid CA, Li NW, Marcoe GJ, Lipinski DM. Prostaglandin-based rAAV-mediated glaucoma gene therapy in Brown Norway rats. Commun Biol 2022; 5:1169. [PMID: 36329259 PMCID: PMC9633612 DOI: 10.1038/s42003-022-04134-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 10/19/2022] [Indexed: 11/06/2022] Open
Abstract
Prostaglandin analogs are first-line treatments for open angle glaucoma and while effective at lowering intraocular pressure, they are undermined by patient non-compliance, causing atrophy of the optic nerve and severe visual impairment. Herein, we evaluate the safety and efficacy of a recombinant adeno-associated viral vector-mediated gene therapy aimed at permanently lowering intraocular pressure through de novo biosynthesis of prostaglandin F2α within the anterior chamber. This study demonstrated a dose dependent reduction in intraocular pressure in normotensive Brown Norway rats maintained over 12-months. Crucially, therapy could be temporarily halted through off-type riboswitch activation, reverting intraocular pressure to normal. Longitudinal multimodal imaging, electrophysiology, and post-mortem histology revealed the therapy was well tolerated at low and medium doses, with no major adverse effects to anterior chamber health, offering a promising alternative to current treatment strategies leading to clinically relevant reductions in intraocular pressure without the need for adherence to a daily treatment regimen.
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Affiliation(s)
- Kristina J Chern
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Emily R Nettesheim
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Christopher A Reid
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Nathan W Li
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Gavin J Marcoe
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Daniel M Lipinski
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.
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8
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AAV2-hCHM Subretinal Delivery to the Macula in Choroideremia: Two Year Interim Results of an Ongoing Phase I/II Gene Therapy Trial. Ophthalmology 2022; 129:1177-1191. [PMID: 35714735 DOI: 10.1016/j.ophtha.2022.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 06/03/2022] [Accepted: 06/07/2022] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To assess the safety of the subretinal delivery of a recombinant adeno-associated virus serotype 2 (AAV2) vector carrying a human CHM-encoding cDNA in choroideremia (CHM). DESIGN Prospective, open-label, non-randomized, dose-escalation, phase 1/2 clinical trial. SUBJECTS, PARTICIPANTS, AND/OR CONTROLS Fifteen CHM patients (ages 20-57 years at dosing). METHODS, INTERVENTION, OR TESTING Patients received uniocular subfoveal injections of low dose (up to 5x1010 vector genome (vg) per eye, n=5) or high dose (up to 1x1011 vg per eye, n=10) AAV2-hCHM. Patients were evaluated pre- and post-operatively for two years with ophthalmic examinations, multimodal retinal imaging and psychophysical testing. MAIN OUTCOME Measures: visual acuity (VA), perimetry (10-2 protocol), spectral-domain optical coherence tomography (SD-OCT) and short-wavelength fundus autofluorescence (SW-FAF). RESULTS We detected no vector-related or systemic toxicities. VA returned to within 15 letters of baseline in all but two patients (one developed acute foveal thinning, another patient, a macular hole); the rest showed no gross changes in foveal structure at two years. There were no significant differences between intervention and control eyes in mean light-adapted sensitivity by perimetry, or in the lateral extent of retinal pigment epithelium (RPE) relative preservation by SD-OCT and SW-FAF. Microperimetry showed non-significant (<3SD of the intervisit variability) gains in sensitivity in some locations and participants in the intervention eye. There were no obvious dose-dependent relationships. CONCLUSIONS VA was within 15 letters of baseline after the subfoveal AAV2-hCHM injections in 13/15 (87%) of the patients. Acute foveal thinning with unchanged perifoveal function in one patient and macular hole in a second suggests foveal vulnerability to the subretinal injections. Longer observation intervals will help establish the significance of the minor differences in sensitivities and rate of disease progression observed between intervention and control eyes.
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9
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Morgan JIW, Jiang YY, Vergilio GK, Serrano LW, Pearson DJ, Bennett J, Maguire AM, Aleman TS. Short-term Assessment of Subfoveal Injection of Adeno-Associated Virus-Mediated hCHM Gene Augmentation in Choroideremia Using Adaptive Optics Ophthalmoscopy. JAMA Ophthalmol 2022; 140:411-420. [PMID: 35266957 PMCID: PMC8914909 DOI: 10.1001/jamaophthalmol.2022.0158] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance Subretinal injection for gene augmentation in retinal degenerations forcefully detaches the neural retina from the retinal pigment epithelium, potentially damaging photoreceptors and/or retinal pigment epithelium cells. Objective To use adaptive optics scanning light ophthalmoscopy (AOSLO) to assess the short-term integrity of the cone mosaic following subretinal injections of adeno-associated virus vector designed to deliver a functional version of the CHM gene (AAV2-hCHM) in patients with choroideremia. Design, Setting, and Participants This longitudinal case series study enrolled adult patients with choroideremia from February 2015 to January 2016 in the US. To be included in the study, study participants must have received uniocular subfoveal injections of low-dose (5 × 1010 vector genome per eye) or high-dose (1 × 1011 vector genome per eye) AAV2-hCHM. Analysis began February 2015. Main Outcomes and Measures The macular regions of both eyes were imaged before and 1 month after injection using a custom-built multimodal AOSLO. Postinjection cone inner segment mosaics were compared with preinjection mosaics at multiple regions of interest. Colocalized spectral-domain optical coherence tomography and dark-adapted cone sensitivity was also acquired at each time point. Results Nine study participants ranged in age from 26 to 50 years at the time of enrollment, and all were White men. Postinjection AOSLO images showed preservation of the cone mosaic in all 9 AAV2-hCHM-injected eyes. Mosaics appeared intact and contiguous 1 month postinjection, with the exception of foveal disruption in 1 patient. Optical coherence tomography showed foveal cone outer segment shortening postinjection. Cone-mediated sensitivities were unchanged in 8 of 9 injected and 9 of 9 uninjected eyes. One participant showed acute loss of foveal optical coherence tomography cone outer segment-related signals along with cone sensitivity loss that colocalized with disruption of the mosaic on AOSLO. Conclusions and Relevance Integrity of the cone mosaic is maintained following subretinal delivery of AAV2-hCHM, providing strong evidence in support of the safety of the injections. Minor foveal thinning observed following surgery corresponds with short-term cone outer segment shortening rather than cone cell loss. Foveal cone loss in 1 participant raises the possibility of individual vulnerability to the subretinal injection.
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Affiliation(s)
- Jessica I W Morgan
- Scheie Eye Institute, University of Pennsylvania, Philadelphia.,Center for Advanced Retinal & Ocular Therapeutics, University of Pennsylvania, Philadelphia
| | - Yu You Jiang
- Scheie Eye Institute, University of Pennsylvania, Philadelphia.,Center for Advanced Retinal & Ocular Therapeutics, University of Pennsylvania, Philadelphia
| | - Grace K Vergilio
- Scheie Eye Institute, University of Pennsylvania, Philadelphia.,Center for Advanced Retinal & Ocular Therapeutics, University of Pennsylvania, Philadelphia
| | - Leona W Serrano
- Scheie Eye Institute, University of Pennsylvania, Philadelphia.,Center for Advanced Retinal & Ocular Therapeutics, University of Pennsylvania, Philadelphia
| | - Denise J Pearson
- Scheie Eye Institute, University of Pennsylvania, Philadelphia.,Center for Advanced Retinal & Ocular Therapeutics, University of Pennsylvania, Philadelphia
| | - Jean Bennett
- Scheie Eye Institute, University of Pennsylvania, Philadelphia.,Center for Advanced Retinal & Ocular Therapeutics, University of Pennsylvania, Philadelphia
| | - Albert M Maguire
- Scheie Eye Institute, University of Pennsylvania, Philadelphia.,Center for Advanced Retinal & Ocular Therapeutics, University of Pennsylvania, Philadelphia
| | - Tomas S Aleman
- Scheie Eye Institute, University of Pennsylvania, Philadelphia.,Center for Advanced Retinal & Ocular Therapeutics, University of Pennsylvania, Philadelphia
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10
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Molecular Characterization of Choroideremia-Associated Deletions Reveals an Unexpected Regulation of CHM Gene Transcription. Genes (Basel) 2021; 12:genes12081111. [PMID: 34440285 PMCID: PMC8392058 DOI: 10.3390/genes12081111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 12/03/2022] Open
Abstract
Choroideremia (CHM) is a X-linked recessive chorioretinal dystrophy due to deficiency of the CHM gene product, i.e., Rab escort protein isoform 1 (REP1). To date, gene therapy for CHM has shown variable effectiveness, likely because the underlying pathogenic mechanisms as well as genotype-phenotype correlation are not yet fully known. Small nucleotide variants leading to premature termination codons (PTCs) are a major cause of CHM, but about 20% of patients has CHM gene deletions. To improve understanding of the disease mechanisms, we analyzed molecular features of seven deletions involving the CHM gene sequence. We mapped the deletion breakpoints by using polymerase chain reaction, sequencing and array comparative genomic hybridization; to identify rearrangement-promoting DNA sequences, we analyzed genomic architecture surrounding the breakpoint regions. Moreover, in some CHM patients with different mutation types, we measured transcript level of CHM and of CHML, encoding the REP2 isoform. Scattered along the whole CHM gene and in close proximity to the deletion breakpoints we found numerous repeat elements that generate a locus-specific rearrangement hot spot. Unexpectedly, patients with non-PTC variants had increased expression of the aberrant CHM mRNA; CHML expression was higher than normal in a patient lacking CHM and its putative regulatory sequences. This latest evidence suggests that mechanisms regulating CHM and CHML gene expression are worthy of further study, because their full knowledge could be also useful for developing effective therapies for this hitherto untreatable inherited retinal degeneration.
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11
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Bansal M, Acharya S, Sharma S, Phutela R, Rauthan R, Maiti S, Chakraborty D. CRISPR Cas9 based genome editing in inherited retinal dystrophies. Ophthalmic Genet 2021; 42:365-374. [PMID: 33821751 DOI: 10.1080/13816810.2021.1904421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Precision genome engineering, with targeted therapy towards patient-specific mutations is predicted to be the future of personalized medicine. Ophthalmology is in the frontiers of development of targeted therapy since the eye is an accessible organ and has the ease of both delivery as well as monitoring effects of therapy. MATERIALS AND METHODS We reviewed literature using keywords CRISPR, precision medicine, genomic editing, retinal dystrophies, retinitis pigmentosa, Usher syndrome, Stargardt's Disease. Further, we collated data on current clinical trials. RESULTS There is growing evidence on the role of genomic editing in retinal dystrophies, the various methods used, and stage of development of different therapies have been summarized in this paper. CONCLUSIONS The CRISPR-Cas9 system has revolutionized genome editing, and opened avenues in drug discovery. It is important to understand the role of this system along with its applicability in the field of ophthalmology. In this review article, we briefly describe its methodology, the strategies of employing it for making genetic perturbations, and explore its applications in inherited retinal dystrophies.
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Affiliation(s)
- Mayank Bansal
- Council of Scientific and Industrial Research - Institute of Genomics & Integrative Biology, New Delhi, India.,Academy of Scientific & Innovative Research, Ghaziabad, India
| | - Sundaram Acharya
- Council of Scientific and Industrial Research - Institute of Genomics & Integrative Biology, New Delhi, India.,Academy of Scientific & Innovative Research, Ghaziabad, India
| | - Saumya Sharma
- Council of Scientific and Industrial Research - Institute of Genomics & Integrative Biology, New Delhi, India.,Academy of Scientific & Innovative Research, Ghaziabad, India
| | - Rhythm Phutela
- Council of Scientific and Industrial Research - Institute of Genomics & Integrative Biology, New Delhi, India.,Academy of Scientific & Innovative Research, Ghaziabad, India
| | - Riya Rauthan
- Council of Scientific and Industrial Research - Institute of Genomics & Integrative Biology, New Delhi, India.,Academy of Scientific & Innovative Research, Ghaziabad, India
| | - Souvik Maiti
- Council of Scientific and Industrial Research - Institute of Genomics & Integrative Biology, New Delhi, India.,Academy of Scientific & Innovative Research, Ghaziabad, India
| | - Debojyoti Chakraborty
- Council of Scientific and Industrial Research - Institute of Genomics & Integrative Biology, New Delhi, India.,Academy of Scientific & Innovative Research, Ghaziabad, India
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12
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Birtel J, Yusuf IH, Priglinger C, Rudolph G, Charbel Issa P. Diagnosis of Inherited Retinal Diseases. Klin Monbl Augenheilkd 2021; 238:249-259. [PMID: 33784788 DOI: 10.1055/a-1388-7236] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Inherited retinal diseases are a frequent cause of severe visual impairment or blindness in children and adults of working age. Across this group of diseases, there is great variability in the degree of visual impairment, the impact on everyday life, disease progression, and the suitability to therapeutic intervention. Therefore, an early and precise diagnosis is crucial for patients and their families. Characterizing inherited retinal diseases involves a detailed medical history, clinical examination with testing of visual function, multimodal retinal imaging as well as molecular genetic testing. This may facilitate a distinction between different inherited retinal diseases, as well as a differentiation from monogenic systemic diseases with retinal involvement, and from mimicking diseases.
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Affiliation(s)
- Johannes Birtel
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.,Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Imran H Yusuf
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.,Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Claudia Priglinger
- Department of Ophthalmology, University Hospital, LMU Munich, Munich, Germany
| | - Günter Rudolph
- Department of Ophthalmology, University Hospital, LMU Munich, Munich, Germany
| | - Peter Charbel Issa
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.,Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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13
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Cehajic-Kapetanovic J, McClements ME, Whitfield J, Shanks M, Clouston P, MacLaren RE. Association of a Novel Intronic Variant in RPGR With Hypomorphic Phenotype of X-Linked Retinitis Pigmentosa. JAMA Ophthalmol 2020; 138:1151-1158. [PMID: 32970112 PMCID: PMC7516822 DOI: 10.1001/jamaophthalmol.2020.3634] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Importance Pathogenic variants in retinitis pigmentosa GTPase regulator (RPGR) gene typically lead to a severe form of X-linked retinitis pigmentosa, which is associated with early severe vision loss. Objective To investigate an X-linked retinal degeneration family with atypical preservation of visual acuity in the presence of a novel deep intronic splice site RPGR c.779-5T>G variant. Design, Setting, and Participants In this case series, 3 members of an X-linked retinal degeneration family were studied by in-depth phenotyping and genetic screening at a single center. Data were collected and analyzed from November 2018 to March 2020. Main Outcomes and Measures Data were collected on full ophthalmic history, examination, and retinal imaging. A full retinitis pigmentosa gene panel was analyzed by next-generation sequencing. The pathogenicity of the RPGR c.779-5T>G variant was assessed by in silico splice prediction tools and by purpose-designed in vitro splicing assay. Results An 84-year-old man was referred with clinical diagnosis of choroideremia and possible inclusion into a gene therapy trial. He presented with late-stage retinal degeneration and unusually preserved visual acuity (78 and 68 ETRDS letters) that clinically resembled choroideremia. His 23-year-old grandson was still in early stages of degeneration but showed a very different clinical picture, typical of retinitis pigmentosa. Next-generation sequencing identified a sole RPGR c.779-5T>G variant of undetermined pathogenicity in both cases. The daughter of the proband showed an RPGR carrier phenotype and was confirmed to carry the same variant. The molecular analysis confirmed that the RPGR c.779-5T>G variation reduced the efficiency of intron splicing compared with wild type, leading to a population of mutant and normal transcripts. The predicted consequences of the pathogenic variant are potential use of an alternative splice acceptor site or complete skipping of exon 8, resulting in truncated forms of the RPGR protein with different levels of glutamylation. Conclusions and Relevance These results support the importance of careful interpretation of inconsistent clinical phenotypes between family members. Using a molecular splicing assay, a new pathogenic variant in a noncoding region of RPGR was associated with a proportion of normal and hypomorphic RPGR, where cones are likely to survive longer than expected, potentially accounting for the preserved visual acuity observed in this family.
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Affiliation(s)
- Jasmina Cehajic-Kapetanovic
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, England
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, England
| | - Michelle E. McClements
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, England
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, England
| | - Jennifer Whitfield
- Genetics Laboratories, Churchill Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, England
| | - Morag Shanks
- Genetics Laboratories, Churchill Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, England
| | - Penny Clouston
- Genetics Laboratories, Churchill Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, England
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, England
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, England
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14
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Talib M, Boon CJF. Retinal Dystrophies and the Road to Treatment: Clinical Requirements and Considerations. Asia Pac J Ophthalmol (Phila) 2020; 9:159-179. [PMID: 32511120 PMCID: PMC7299224 DOI: 10.1097/apo.0000000000000290] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/01/2020] [Indexed: 12/15/2022] Open
Abstract
: Retinal dystrophies (RDs) comprise relatively rare but devastating causes of progressive vision loss. They represent a spectrum of diseases with marked genetic and clinical heterogeneity. Mutations in the same gene may lead to different diagnoses, for example, retinitis pigmentosa or cone dystrophy. Conversely, mutations in different genes may lead to the same phenotype. The age at symptom onset, and the rate and characteristics of peripheral and central vision decline, may vary widely per disease group and even within families. For most RD cases, no effective treatment is currently available. However, preclinical studies and phase I/II/III gene therapy trials are ongoing for several RD subtypes, and recently the first retinal gene therapy has been approved by the US Food and Drug Administration for RPE65-associated RDs: voretigene neparvovec-rzyl (Luxturna). With the rapid advances in gene therapy studies, insight into the phenotypic spectrum and long-term disease course is crucial information for several RD types. The vast clinical heterogeneity presents another important challenge in the evaluation of potential efficacy in future treatment trials, and in establishing treatment candidacy criteria. This perspective describes these challenges, providing detailed clinical descriptions of several forms of RD that are caused by genes of interest for ongoing and future gene or cell-based therapy trials. Several ongoing and future treatment options will be described.
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Affiliation(s)
- Mays Talib
- Department of Ophthalmology, Leiden, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden, The Netherlands
- Department of Ophthalmology, Amsterdam UMC, Academic Medical Center, University of Amsterdam. Amsterdam, The Netherlands
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15
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Menghini M, Cehajic-Kapetanovic J, MacLaren RE. Monitoring progression of retinitis pigmentosa: current recommendations and recent advances. Expert Opin Orphan Drugs 2020; 8:67-78. [PMID: 32231889 PMCID: PMC7104334 DOI: 10.1080/21678707.2020.1735352] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/24/2020] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Retinitis pigmentosa (RP) is the most common form of inherited retinal degenerations with an estimated prevalence of 1 in 4,000 and more than 1 million individuals affected worldwide. With the introduction of the first retinal gene therapy in 2017 the importance of understanding the mechanisms of retinal degeneration and its natural progression has shifted from being of academic interest to being of pivotal for the development of new therapies. AREAS COVERED This review covers standard and innovative diagnostic techniques and complementary examinations needed for the evaluation and treatment of RP. It includes chapters on the assessment of visual function, retinal morphology, and genotyping. EXPERT OPINION Monitoring the progression of RP can best be achieved by combining assessments of both visual function and morphology. Visual acuity testing using ETDRS charts should be complemented by low-luminance visual acuity and colour vision tests. Assessment of the visual field can also be useful in less advanced cases. In those with central RP involvement measuring retinal sensitivity using microperimetry is recommended. Retinal morphology is best assessed by OCT and autofluorescence. Genetic testing is pivotal as it contributes to the pathophysiological understanding and can guide clinical management as well as identify individuals that could benefit from retinal gene therapy.
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Affiliation(s)
- Moreno Menghini
- Oxford Eye Hospital and Nuffield Department of Clinical Neurosciences, Oxford University, The John Radcliffe Hospital, West Wing, Oxford OX3 9DU, United Kingdom, +41 79 704 52 58
| | - Jasmina Cehajic-Kapetanovic
- Oxford Eye Hospital and Nuffield Department of Clinical Neurosciences, Oxford University, The John Radcliffe Hospital, West Wing, Oxford OX3 9DU, United Kingdom, +44 7725 197054
| | - Robert E MacLaren
- Oxford Eye Hospital and Nuffield Department of Clinical Neurosciences, Oxford University, The John Radcliffe Hospital, West Wing, Oxford OX3 9DU, United Kingdom, +44 1865 228974
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